Bipolar vacuum-electrode.



Nb. 791,572. PATENTED JUNE 6, 1905.

E. L. OVINGTON. I BIPOLAR VACUUM ELECTRODE.

'AIILIOATION rILEn MAE. s, 1905.

gnveni'oz Patented June 6, 1905.

PATENT OFFICE.

EARLE L. OVI NGTON, OF BOSTON, MASSACHUSETTS.

BIPOLAR VACUUM-ELECTRODE.

SPECIFICATION formingpart of Letters Patent No. 791,572, dated June 6,1905.

Application filed March 6 1905. Serial No. 248,722.

To all whom it may concern.-

Be it known that I, EARLE L. OVINGTON, a

citizen of the United States, and a resident of Boston, in the county ofSufiolk and State of Massachusetts, have invented certain new and usefulImprovements in Bipolar Vacuum- Electrodes, of which the following is aspecification.

This invention relates to an improvement in vacuum-electrodes, by whichterm is meant those forms of electrodes comprising in the main of aninsulating material, usually glass, inclosing a gaseous medium, usuallyrarefied air, said electrodes being adapted for use in connection withcurrents of high potential and preferably high frequency.

The object of my invention is to provide an electrode suitable forlocalizing the effects produced and concentrating the action at thepoint of application.

I accomplish my object by providing a bipolar electrode instead of themonopolar one usually employed.

In the treatment of disease by means of high-potential high-frequencycurrents it is commonpractice to connect the patient with one terminalof the source of energy, the other terminal being connected to avacuum-electrode, which electrode is then applied to the affected part.Under certain circumstances the direct connection of the patient withthe generating source is discarded, the only connection being thenthrough the-vacuum-elec trode. Whichever method of treatment is employeda monopolar electrode is used, said electrode being connected With onlyone terminal of the current source.

Oneof the greatest disadvantages inherent in both of the above methodsof treatment employing a monopolar electrode is due to the fact that thepatient not only receives the desired local treatment produced byapplication of the electrode to the affected part, but receives ageneral treatment due to the fact that he is connected to one or bothterminals of the machine. Where the potential and frequency of thecurrent supplied are both high, this incidental general treatment mustoften be made objectionally rigorous in order to obtain the desiredlocal effect. In certain cases,

notably where the patient is unusually sensitive or nervously excited,this general treatment is not desirable.

Another undesirable feature present when employing the above-mentionedmethods of treatment is the unpleasant sparking which takes place whenthe electrode is brought near to the body of the patient in the act ofplacing it in actual contact. When the electrode is a short distancefrom the flesh or when an insulating medium, such as an article ofclothing, lies between the electrode and the affected part, anirritating sparking takes place 1 across the intervening dielectric,which sparking is often suflicient to redden the skin to a 5 perceptibledegree. This at times is very distressing, especially in the case of theaffected part being oversensitive. 'In such an instance resort is oftenmade to the expedient of decreasing the energy flowing through 7 theelectrode, which means that a correspondingly longer treatment must begiven to accomplish the desired result.

Another disadvantage of the system mentioned, which employs a monopolarelectrode with the single. terminal connection, is that it is limited toapparatus producing electricity of high potential, since the current inthe electrode is only that which flows to the body of the patient, dueto the condenser action of the patient with respect to the current. Nowthe energy which flows into a condenser is a function of the potential,and the capacity ofthe human body is small. For this reason a highpotential must be employed in connec- 5 tion with a monopolar electrodeconnected with only one terminal of the generating source.

Still another undesirable feature of the monopolar method is due to thefact that the 9 current used in the electrode must pass through theresistance of the body in addition to the usual contact and electroderesistance. This means a decreased current-flow for a given potential.Then again the current which can be comfortably borne by the patient'isless when the current has to pass through the whole body than when thepath is from one electrode of a bipolar system through the affected partto the other electrode. Hence, I00

other things being equal, a longer treatment is necessary when employinga monopolar electrode than is the case when a bipolar electrode isutilized.

I have overcome all of the above disadvantages by providing abipolarvacuum-electrode. By employing my bipolar electrode the treatment of theaffected part may be localized and the undesirable general treatmentabove mentioned done away with, since the tendency of the current is toflow from one terminal of the electrode through the affected tissue tothe other terminal, the current having practically no tendency to flowto other parts of the body.

By employing my bipolar electrode the disagreeable sparking mentioned inconnection with monopolar electrodes is eliminated. This is due to apeculiar phenomenon which I have discovered. If the two terminals of mybipolar electrode be connected to a source of high-potentialhigh-frequency currents, the current turned on, and the electrode heldout of contact with conducting substances, the current flows from oneterminal of the electrode through the intervening dielectric to theother terminal. In this case the flow of current is confined to theneighborhood of the electrode itself. If now a conducting body, such asthe human flesh, be brought into contact with the two terminals of theelectrode, the current ceases to flow directly from one terminal of theelectrode to the other and now takes a course from one terminal throughthe affected part to the other terminal. Under such conditions thispeculiar effect is due to capacity phenomena. In each case theconducting gaseous medium of the electrode-terminals form two plates ofa condenser. In each case the conducting material of which thevacuumelectrode is constructed forms part of the dielectric between theplates. The difference lies in the factthat in the first case that inwhich the electrode is not in contact with the patient-the path throughthe dielectric is of high resistance, while in the sec- 0nd case, wherethe electrode is in contact with the patient, the path through thedielectric is of comparatively low resistance, the patients body being agood conductor for such high-potential currents as those employed. Forthis reason the current is confined to the electrode when same is not inuse, but immediately appears at the surface of the electrode when sameis brought into contact with the body of a patient. I take advantage ofthis phenomenon in constructing my electrode, with the result that theirritating sparking above referred to is eliminated. In just thatproportion to the amount the electrode is in contact with the afiectedpart does the current flow through the diseased tissue or other part ofthe body under treatment. The rest of the current flows inside theelectrode instead of causing disagreeable sparks.

On account of the fact that my bipolar electrode has its terminals closetogether it may be employed in connection with potentials far below thepoint where the monopolar electrodes become inoperative. This greatlywidens the field of operation.

Having thus outlined the advantages of my invention and briefly statedthe theory upon which its operation is based, 1 will now describe itsconstruction in detail, reference being had to the drawings accompanyingand forming a part of this specification.

Figure 1 is the plan view of one form in which my bipolar electrode maybe made, while Fig. 2 is a side elevation of same. Fig. 3 shows anotherconstruction incorporating the principle of my invention. 1 have foundglass to be the most suitable material for use in construction of theelectrodes, although any other suitable insulating material might beemployed.

Referring to Figs. 1 and 2, 2 2 are tubular pieces of glass, upon theends of which are blown the bulbs 1 1, which are subsequently flattened,as shown. Terminals 3 3 serve to lead the current into the compartmentsthus formed, said compartments being exhausted or otherwise treated, sothat they contain a rarefied gaseous medium. The portion 4 serves tomechanically, although not electrically, connect the two vacuumcompartments, thus forming a double or bipolar electrode which may beused in connection with the various electrode-handles employed with theusual form of monopolar electrodes.

Fig. 3 shows another form my bipolar electrode may take, it beingespecially designed for use in the treatment of certain cavities of thehuman body. Referring to the figure, 9 is a glass tubular portion whichconstitutes the exterior wall of the electrode. The compartment 10 ispartitioned off, as shown, and is connected through the interiorterminal 11 by means of the Wire 12 with the external terminal l3. 14 isa compartment formed so as to surround the wire 12, said compartmentbeing connected, through internal terminal 15 by means of wire 16, withthe external terminal 17. The remaining space constitutes the largestcompartment 18. The smaller compartments 10 and 14 are exhausted to alow vacuum, which makes them agood conductor of high-tensionelectricity. The largest compartment 18 is exhausted to the highestattainable vacuum, which makes itavery poor conductor of electricity,thus insulating the wires 12 and 16 from each other, as well as the twosmaller compartments 10 and 14. When this electrode is introduced into acavity of the body, a condenser is formed, the conducting-compartments10 and 14 comprising the condenser-plates, while the external walls ofthe electrode and the surface of the cavity form the dielectric of thecondenser. The

current therefore passes from one compartdicated the terminals whichlead the current into the conducting-compartments of the electrode asbeing internal terminals penetrating the walls of the compartments. Withcertain forms of currents, notably those having high potential andfrequency, it is not necessary to employ leadingin terminals of theabove type. Under such conditions it is only necessary to makeconnection with conducting-surfaces attached to the exterior of theglass tubular portion. It is of course understood that my inventionoperates with either type of terminal.

I believe it is broadly new to employ a bipolar vacuum-electrode in thetreatment of disease, the term bipolar vacuum-electrode being applied toan electrode adapted for connection with both terminals of thegenerating source, the current passing from one conducting portion ofthe electrode to the other through the affected part of the body undertreatment.

In the drawings I have not attempted to e um is meant rarefied air,although it is evident that any other suitable conducting gaseous mediumcould be used in connection with my invention, and same is intended toembrace such modifications.

This invention must not be confounded with bipolar vacuum-tubes devisedto generate various kinds of visible and ultraviolet radiations. Myinvention may be differentiated from the above class by noting that inapplying my invention a portion of the patient forms part of theelectric circuit from one terminal of the electrode to the other, whilein the tubes above mentioned this is not the case.

I claim as new is- 1. A bipolar vacuum-electrode for therapeutictreatment of such a construction that the electric circuit through theelectrode may be completed by the body of a patient.

2. A bipolar vacuum-electrode for therapeutic treatment of such aconstruction that the electric current, in passing from one terminal ofthe electrode to the other, may flow through the part of the body of apatient to which the electrode is applied.

3. 'A bipolar vacuum-electrode for therapeutic treatment, adapted forconnection with the two terminals of the source of electricity,

the construction of the electrode being such that the current in passingfrom vone terminal of the electrode to the other, is compelled to flowthrough the aflected part under treatment.

4. A bipolar electrode comprising inclosed gaseous conductors. saldconductors being insulated from each other and provided with a means ofconnection with the source of current.

5. Abipolar electrode comprising two insulated compartments,saidcompartments containing a gaseous conductor, means for supporting thecompartments in proximity to each other, and means for connecting thegaseous conductors with the source of current.

6. A bipolarelectrode, comprising gaseous conductors in mechanical butnot electrical connection with each other; means for connecting thegaseous conductors to the source of current-supply, the constructionbeing such that when the electrode is used for treatment the currentflows from one gaseous conductor to the other through the diseased part;

7. A bipolar vacuum-electrode for therapeutic treatment comprising twoglass compartments from which the air has been partially exhausted,means for mechanically but not electrically connecting saidcompartments, and means for electrically connecting the compartmentswith the source of current.

In testimony whereof I have affixed my signature in presence of twowitnesses.

,EARLE L. OVINGTON.

Witnesses:

WM. 0. EDDY, E. J. OVINGTON.

